The disclosure generally relates to a wireless LAN communication device and, more particularly, to the wireless LAN communication device which may reduce the impacts of the adjacent channel interference signals.
Many countries have reserve some radio bands for developing industrial, scientific, and medical applications, i.e., the industrial, scientific and medical radio bands (the ISM band). The wireless local area network (LAN) communication devices utilize the ISM band to perform communications, and have been successfully adopted in many applications.
Many other communication devices (e.g., the Bluetooth devices and the cordless telephones) also perform communications in the same or neighboring frequency bands in ISM band, and results in the impacts on the communication performance of the wireless LAN communication devices.
Moreover, the wireless LAN communication devices in different basic service sets may become interference signals to one another. For example, when a wireless LAN communication device is associated with a first access point, it may still receive the wireless signals transmitted from a second access point in another basic service set. Even if the second access point uses a different channel from the first access point, the adjacent channel interference still influences the communication performance between the wireless LAN communication device and the first access point. If the signals from the first access point and the second access point are received at the same time or at a similar time, the wireless LAN communication device may start the demodulation operations on the signals transmitted from the second access point. After the demodulation circuit of the wireless LAN communication device finds out that the signals are not transmitted from the first access point, the signals transmitted from the first access point cannot be received and demodulated. Thus, the communication performance between the wireless LAN device and the associated first access point may be seriously impacted.
Furthermore, when the signal strengths of the adjacent channel interference signals are strong, some receiver circuits of the wireless LAN communication device may be also saturated, e.g., the low-noise amplifying circuit. The demodulation performance and the communication performance deteriorate accordingly. Along with the wider adoption of the wireless LAN communication devices, the adjacent channel interference will result in the impacts on the communication performance and the inconvenience of the users.